Biomedical subjects
Publications and source records attributed to D Baskin.
Lymphomatoid granulomatosis is an angiocentric lymphoreticular proliferative disease. Some patients go on to develop frank neoplasia. The authors describe a patient who presented at the age of 12 years with pulmonary nodules and hepatosplenomegaly and was followed up for 6 years, and who subsequently developed lymphoma after cessation of therapy.
Accumulating evidence indicates that the central melanocortin (MC) system plays a key role in the regulation of food intake and energy balance. This evidence includes findings that either spontaneous genetic mutations or targeted gene deletions that impair melanocortin signaling cause disrupted food intake and body-weight control. In addition, expression of the mRNA that encodes the endogenous agonists and antagonists for CNS melanocortin receptors is regulated by changes in energy balance and body-adiposity signals. Finally, administration of both natural and synthetic ligands to MC receptors produces changes in food intake. The data collectively suggest a critical role for melanocortin signaling in the control of energy balance.
A case of an incomplete Currarino triad is reported. The baby underwent an emergency laparotomy due to a life-threatening intestinal obstruction caused by severe rectal stenosis. During the posterosagittal anorectoplasty (PSARP), a presacral teratoma was identified and resected. The tumor recurred three times; she initially responded to chemotherapy, but nonetheless died at the age of 4 years. In cases with evidence of anorectal stenosis, a presacral mass should be suspected. PSARP is the best choice of treatment for both the anorectal anomaly and excision of the presacral mass. The presacral region should be followed up closely for recurrence of the tumor.
Most of the foreign bodies swallowed by children pass the entire gastrointestinal tract without any complication. Neonatal intestinal foreign bodies are extremely rare. A newborn with a small bowel obstruction caused by a fresh grape is reported.
In a training center, 1,131 inguinal hernias were repaired in 1,000 consecutive patients in 6 years. The documents of these patients were reviewed retrospectively for surgical complications. A total of 38 complications were encountered in 35 patients, including wound infection (1.9%), recurrence (0.9%), tethered testis (0.3%), bladder injury (0.3%), was deferens injury (0.2%), iatrogenic orchiectomy (0.1%), and postoperative death. Most of them occurred in the early years of the clinic, and nearly one-half were technical in nature. Careful training, stressing the importance of gentle handling of the tissues, and meticulous dissection with emphasis on learning groin anatomy should reduce the incidence of such complications.
Unilateral torsion of the spermatic cord has been demonstrated to damage the contralateral testis; however, the pathogenesis has not yet been examined in detail. The purpose of this study was to evaluate the influence of unilateral torsion on the contralateral testis in rats by performing ipsilateral division of the genitofemoral nerve (GFN) and/or late orchiectomy. Male 25-day-old, prepubertal Wistar albino rats were divided into five groups: (1) sham operation; (2) unilateral testicular torsion; (3) simultaneous unilateral testicular torsion and ipsilateral GFN division; (4) unilateral testicular torsion and orchiectomy on the 4th day after torsion; and (5) simultaneous unilateral testicular torsion and GFN ipsilateral division, and orchiectomy on the 4th day after torsion. Torsions performed were 720 degrees, all on the right testes. On day 55 after torsion, which represents the early postpubertal period of the rat, the contralateral testes were removed. Tubular biopsy score (TBS) was calculated, and seminiferous tubular diameters (STD) were measured. Student's t-test was used for statistical analysis. There was no contralateral testicular damage in the control group, but in all of the study groups destructive changes were found in the left gonad after torsion of the right testicle. The mean TBS of the study groups was higher than that of the control group. STD values were lower in the study groups, but the differences were not statistically significant between groups. In prepubertal rats, unilateral torsion causes histologically measurable changes in the contralateral testis. Ipsilateral division of the GFN and late orchiectomy did not cause any significant alterations in terms of contralateral damage. Further investigations are needed to determine the role of the GFN in testicular torsion.
The prion protein (PrP), first identified in scrapie-infected rodents, is encoded by a single exon of a single-copy chromosomal gene. In addition to the protein-coding exon, PrP genes in mammals contain one or two 5'-noncoding exons. To learn more about the genomic organization of regions surrounding the PrP exons, we sequenced 10(5) bp of DNA from clones containing human, sheep, and mouse PrP genes isolated in cosmids or lambda phage. Our findings are as follows: (1) Although the human PrP transcript does not include the untranslated exon 2 found in its mouse and sheep counterparts, the large intron of the human PrP gene contains an exon 2-like sequence flanked by consensus splice acceptor and donor sites. (2) The mouse Prnpa but not the Prnpb allele found in 44 inbred lines contains a 6593 nucleotide retroviral genome inserted into the anticoding strand of intron 2. This intracisternal A-particle element is flanked by duplications of an AAGGCT nucleotide motif. (3) We found that the PrP gene regions contain from 40% to 57% genome-wide repetitive elements that independently increased the size of the locus in all three species by numerous mutations. The unusually long sheep PrP 3'-untranslated region contains a "fossil" 1.2-kb mariner transposable element. (4) We identified sequences in noncoding DNA that are conserved between the three species and may represent biologically functional sites.
Extremely halophilic archaea, which flourish in hypersaline environments, are known to contain a variety of large dynamic replicons. Previously, the analysis of one such replicon, pNRC100, in Halobacterium sp. strain NRC-1, showed that it undergoes high-frequency insertion sequence (IS) element-mediated insertions and deletions, as well as inversions via recombination between 39-kb-long inverted repeats (IRs). Now, the complete sequencing of pNRC100, a 191,346-bp circle, has shown the presence of 27 IS elements representing eight families. A total of 176 ORFs or likely genes of 850-bp average size were found, 39 of which were repeated within the large IRs. More than one-half of the ORFs are likely to represent novel genes that have no known homologs in the databases. Among ORFs with previously characterized homologs, three different copies of putative plasmid replication and four copies of partitioning genes were found, suggesting that pNRC100 evolved from IS element-mediated fusions of several smaller plasmids. Consistent with this idea, putative genes typically found on plasmids, including those encoding a restriction-modification system and arsenic resistance, as well as buoyant gas-filled vesicles and a two-component regulatory system, were found on pNRC100. However, additional putative genes not expected on an extrachromosomal element, such as those encoding an electron transport chain cytochrome d oxidase, DNA nucleotide synthesis enzymes thioredoxin and thioredoxin reductase, and eukaryotic-like TATA-binding protein transcription factors and a chromosomal replication initiator protein were also found. A multi-step IS element-mediated process is proposed to account for the acquisition of these chromosomal genes. The finding of essential genes on pNRC100 and its property of resistance to curing suggest that this replicon may be evolving into a new chromosome.
Expression of Thermus aquaticus (Taq) DNA polymerase I (pol I) in Escherichia, coli complements the growth defect caused by a temperature-sensitive mutation in the host pol I. We replaced the nucleotide sequence encoding amino acids 659-671 of the O-helix of Taq DNA pol I, corresponding to the substrate binding site, with an oligonucleotide containing random nucleotides. Functional Taq pol I mutants were selected based on colony formation at the nonpermissive temperature. By using a library with 9% random substitutions at each of 39 positions, we identified 61 active Taq pol I mutants, each of which contained from one to four amino acid substitutions. Some amino acids, such as alanine-661 and threonine-664, were tolerant of several or even many diverse replacements. In contrast, no replacements or only conservative replacements were identified at arginine-659, lysine-663, and tyrosine-671. By using a library with totally random nucleotides at five different codons (arginine-659, arginine-660, lysine-663, phenylalanine-667, and glycine-668), we confirmed that arginine-659 and lysine-663 were immutable, and observed that only tyrosine substituted for phenylalanine-667. The two immutable residues and the two residues that tolerate only highly conservative replacements lie on the side of O-helix facing the incoming deoxynucleoside triphosphate, as determined by x-ray analysis. Thus, we offer a new approach to assess concordance of the active conformation of an enzyme, as interpreted from the crystal structure, with the active conformation inferred from in vivo function.
Explore the source record for details and available documents.
Although there is an increase in attention being paid to race and sex variations in crime and delinquency, little has been done to disaggregate the "gender-ratio" problem in order to account for participation in particular offenses, specifically different types of violent crime. Virtually all of the research pertaining to the interaction of gender, race and -violent crime focuses on murder and dichotomizes race into white and black, or white and nonwhite. This paper uses New York City arrest data to examine the extent of violence within various race-sex-crime subgroups. Rates of violent offending (i.e., homicide, robbery, assault, and burglary) are presented for black, Hispanic and white males and females. Regardless of violent crime type, black and Hispanic females exhibited high rates of offending relative to white females. Furthermore, the violent offending rates of black females paralleled those of white males. These findings suggest that an examination of gender differences in violent offending, independent of race, will produce incomplete and potentially misleading interpretations. The paper also provides a social structural explanation of the disproportionate involvement of black females (and males) in violent crime.
Results obtained from a questionnaire regarding termination criteria in psychotherapy, revealed significant differences between the public and private sector. Additional differences were also found for: length of sessions, frequency of sessions, length of treatment, hospitalizations, medication usage, ethnicity, diagnosis, degree of perceived improvement, and degree of clinical improvement.
Alzheimer's disease is the fourth most common cause of death in the United States, and is the leading cause of functional disability in the elderly. This article analyzes the pathologic validity of mental status tests and the biochemistry of Alzheimer's disease patients.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Guinea pigs injected with streptozotocin were significantly hyperglycemic on day 1 after injection but only mildly so on day 14. However, serum insulin levels were significantly depressed on day 14; at this time the animals had lost 25% of their initial body weights and were severely glycosuric. The volume fraction of immunostainable B cells in the pancreas was reduced to one third of control values by day 1 after injection and remained at this level by day 14. Animals that received alloxan were slightly hyperglycemic on day 1 but not day 14. Both serum insulin and volume fraction of B cells in the pancreas were reduced by 70% on day 1 but had returned to control levels by day 14. Body weights for this group were equivalent to controls at both time points. These data indicate that: streptozotocin treatment of guinea pigs causes a diabetes-like condition characterized by insulin deficiency, pancreatic B cell loss, glycosuria, and weight loss, which are not reversed in the first 2 weeks after injection, whereas hyperglycemia is only transitory; alloxan also produces a diabetes-like condition early after injection, but all signs of diabetes disappear within 2 weeks, by which time serum insulin levels and the volume fraction of B cells in the pancreas have returned to normal. The experimental results suggest that regeneration of islet B cells following destruction by alloxan may be the primary cause of the recovery of alloxan-injected guinea pigs from the effects of the drug, whereas the persistence of insulin deficiency is consistent with an absence of islet B cell regeneration in the streptozotocin-treated animals.
Some critics of the community mental health movement have contended that fewer clients with serious mental disorders are seen by local mental health centers. This statewide study compared patients being treated at community health centers (CMHC) with those seen at state psychiatric hospitals in New York State. Minor differences in psychiatric diagnoses and requisite levels of care needed emerged between short-term state psychiatric patients and CMHC inpatients. Suggestions for future research are offered.
Previous published papers by the author addressed the issue of the epidemiology of mental illness across different cultures. This paper departs from this basis and stresses the need for examining mental illness within the context of any given culture. Thus, the application of rigorous criteria, such as those specified by DSM III or ICD-9, to all cultures, regardless of how different behaviors are viewed within the culture is deemed to be specious. Moreover, the treatment of mental illness has been shown to be related to the perception of mental illness within any given culture and is clearly affected by social norms. Mental health professionals from over 20 countries were administered a questionnaire querying whether hypothetical cases would be diagnosed as mentally ill and if so what would be their diagnosis. Differences between professionals were discussed in light of cross-cultural variations. Suggestions for future research are offered.