False-positive pregnancy test associated with gonadoblastoma

Gonadoblastomas are known to be hormonally active tumors that occur in streak or dysgenetic gonads of patients with intersex abnormalities. Several reports document their ability to produce beta-human chorionic gonadotropin (HCG), but none have documented an elevated peripheral serum beta-HCG. We report on the case of a patient with pure gonadal dysgenesis with XY karyotype who was found to have an elevated peripheral serum beta-HCG after a positive pregnancy test. Knowledge of gonadoblastoma's potential to elevate serum beta-HCG levels may prevent unnecessary searches for other causes.     

Long-term discordant xenogeneic (porcine-to-primate) bone marrow engraftment in a monkey treated with porcine-specific growth factors

BACKGROUND: Mixed allogeneic hematopoietic chimerism has previously been reliably achieved and shown to induce tolerance to fully MHC-mismatched allografts in mice and monkeys. However, the establishment of hematopoietic chimerism has been difficult to achieve in the discordant pig-to-primate xenogeneic model. METHODS: To address this issue, two cynomolgus monkeys were conditioned by whole body irradiation (total dose 300 cGy) 6 and 5 days before the infusion of pig bone marrow (BM). Monkey anti-pig natural antibodies were immunoadsorbed by extracorporeal perfusion of monkey blood through a pig liver, immediately before the intravenous infusion of porcine BM (day 0). Cyclosporine was administered for 4 weeks and 15-deoxyspergualin for 2 weeks. One monkey received recombinant pig cytokines (stem cell factor and interleukin 3) for 2 weeks, whereas the other received only saline as a control. RESULTS: Both monkeys recovered from pancytopenia within 4 weeks of whole body irradiation. Anti-pig IgM and IgG antibodies were successfully depleted by the liver perfusion but returned to pretreatment levels within 12-14 days. Methylcellulose colony assays at days 180 and 300 revealed that about 2% of the myeloid progenitors in the BM of the cytokine-treated recipient were of pig origin, whereas no chimerism was detected in the BM of the untreated control monkey at similar times. The chimeric animal was less responsive by mixed lymphocyte reaction to pig-specific stimulators than the control monkey and significantly hyporesponsive when compared with a monkey that had rejected a porcine kidney transplant. CONCLUSION: To our knowledge, this is the first report of long-term survival of discordant xenogeneic BM in a primate recipient.     

Perioperative complications of transseptosphenoidal excision for pituitary adenomas

Although complications of transseptosphenoidal (TSS) pituitary surgery have been discussed in the literature, there has not been an analysis of complication rates related to clinical features and the nature of the tumor. A retrospective review of 366 TSS procedures (354 patients) for excision of pituitary adenomas evaluated the incidence and management of perioperative complications. The mortality rate was 0.82%. The most frequently encountered complications were transient diabetes insipidus (8.74%) and cerebrospinal fluid (CSF) rhinorrhea (4.10%). Other complications included exacerbation of visual acuity and visual field defects, hemorrhage, hydrocephalus, and meningitis. The factors evaluated were gender, age, tumor size, hormone secretory status, and any history of prior pituitary surgery.There was a significantly higher incidence of transient diabetes insipidus in patients with hormone-secreting tumors. Minor and total complication rates were significantly increased in microadenomas, hormone-secreting tumors, in female patients, and in patients less than 60 years of age reflecting the increased incidence of transient diabetes insipidus in young female patients with hormone-secreting tumors. Observed intraoperative CSF leaks predisposed to postoperative CSF rhinorrhea. There were no identifiable risk factors for major complications.     

Small intestinal permeability to mannitol,lactulose, and polyethylene glycol 400 in celiac disease

Mannitol (molecular weight 182), lactulose (342), and polyethylene glycol 400 (range 242–550) absorption was studied in 25 controls, 22 untreated celiacs, and 13 treated celiacs. Untreated celiacs absorbed less mannitol and more lactulose than controls. Absorption of higher as well as lower molecular-weight polyethylene glycols was reduced in untreated celiac disease. Absorption returned towards normal on treatment. Polyethylene glycol and lactulose absorption was enhanced by administering them in a hypertonic solution. Polyethylene glycol 400 but not lactulose or mannitol was lipid solublein vitro. It was concluded that the mucosa in untreated celiac disease was more leaky than normal. Polyethylene glycol 400 absorption data suggested that its absorption may largely be determined by its lipid solubility and was decreased in celiac disease because of the reduced surface area of the small intestine. Polyethylene glycol 400 cannot be recommended as a suitable marker for permeability studies of the small intestine.     

Effects of cerebellar stimulation on epilepsy, the EEG and cerebral palsy in man.

Eighteen of the first 29 patients with intractable epilepsy treated by chronic cerebellar stimulation (CCS) demonstrated a marked suppression of seizures. Sixty-eight of 100 patients with cerebral palsy showed clinical improvement after CCS. Electroencephalographic studies in three epileptic patients revealed a significant (P less than 0.001) reduction in number and duration of paroxysmal EEG discharges during epochs when the stimulator was on; prolonged effects were seen at stimulation rates of 200 c/sec and 10 c/sec (monophasic capacitively coupled stimuli). "Rebound" increases in numbers and durations of paroxysmal discharges occurred after cessation of CCS: immediate "rebounds" occurred within the next 5 min; such rebound effects were also seen in the frequency of clinical seizures. CCS at voltages well above threshold for the production of changes in H reflexes, late motor responses (V1 and V2), and evoked potentials resulted in increased "rebound" effects after cessation of stimulation and such effects were seen clinically and neurophysiologically in epileptic and cerebral palsy patients. Variability in the effects of CCS on seizures and the EEG may have been due to technical factors such as positions and impedances of electrodes, output of the stimulator, effects of anticonvulsant medication and patient differences; there was no clinical or physiological evidence of any undesirable neurological effect of CCS. In one patient, onset of CCS was frequently associated with cessation of polyspike and wave discharges; such results raise the possibility of triggering CCS from paroxysmal discharges in the EEG (contingency feedback) but rebound effects may complicate such therapy.     

Reactions of 'bay-region' and non-'bay-region' diol-epoxides of benz(a)anthracene with DNA: evidence indicating that the major products are hydrocarbon-N2-guanine adducts

The rates of reaction and the products formed when two vicinaldiol-epoxides derived from benz(a)an-thracene, anti-BA-3, 4-dioI1, 2-oxide (t-3, r-4-dihydroxy-t-1, 2-oxy-l, 2, 3, 4-tetrahydrobenz(a)anthracene)^* and anti-BA-8, 9-diol 10, 11-oxide (r-8, t-9-dihydroxy-t-10,ll-oxy-8, 9, 10, ll-tetrahydro-benz(a)anthracene) reacted withDNA were studied in vitro and the results were compared withthose obtained in similar experiments using anti-BP-7, 8-diol9, 10-oxide (r-7, t-8-dihydroxy-t-9, 10-oxy-7, 8, 9, 10-tetrahydrobenzo(a)pyrene).The reactivities appeared to decrease in the order anti-BP-7,8-diol 9, 10-oxide > anti-BA-3, 4-diol 1, 2-oxide anti-BA-8,9-diol 10, 11-oxide. The diol-epoxides reacted to a similarextent with single- and with double-stranded DNA but reactionswith dGMP, at equivalent concentrations, were much slower thanwith DNA. With the diol-epoxides of benz(a)anthracene, two principaladducts were present in DNA hydrolysates and evidence was obtained,based on pK determinations before and after nitrous acid treatment,consistent with their being N²-guanine derivatives, analogousto the known DNA-reaction products of benzo(a)-pyrene 7, 8-diol9, 10-oxide.     

Neuroendocrinology and brain peptides

To date about thirty peptides--low-molecular-weight, single-chain amino acid compounds--are known to be distributed widely in the central nervous system within selective neuron pathways. These findings, combined with a large body of neuropharmacological, behavioral, and electrophysiological data, open new horizons in neurobiology, force a reexamination of old and accepted hypotheses, and hold important implications for the clinician. There is evidence that substance P and the opioid peptides play a major role in the pain pathway, particularly at the level of the spinal cord. Available evidence also implicates vasoactive intestinal polypeptide in the control of cerebral circulation, cholecystokinin in the regulation of appetite, and vasopressin and adrenocorticotropic hormone in memory. Many questions, however, remain. For most peptides there is little information on mechanisms of biosynthesis, release, interaction with receptors, and termination of biological effect. Another important question is the interaction of peptides with other neurotransmitters. The evidence that both "classic" neurotransmitters and peptides can be found in the same neuronal necessitates reformulation of Dale's "one neuron, one neurotransmitter" hypothesis. It may be that a single cell, while containing different classes of neurotransmitter, will contain only one member of any particular class. It is not too early to speculate on the role of the numerous and diverse peptides in neuronal tissue and on the implications of peptide abnormalities in a variety of neurological diseases. The answers to these and other questions pose a fascinating challenge to neurobiologist and clinician alike.