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Biomedical subjects

M J Klein

Publications and source records attributed to M J Klein.

At least 109 records · Page 6Linked to original sources
PubMed1990

Ontogenesis of proopiomelanocortin gene expression and regulation in the rat pituitary intermediate lobe.

During ontogenesis, proopiomelanocortin (POMC) mRNA appears in the pituitary intermediate lobe (IL) at embryonic day 16 (E16), rather later than in the hypothalamic arcuate nucleus (E13) or the pituitary anterior lobe (E15). POMC mRNA onset in the IL correlates with the appearance of POMC-derived peptides detected by immunocytochemistry (ICC), indicating that there is probably no time lag between POMC mRNA translation. Subsequently, while the IL lobular organization developed progressively, the number of in situ hybridization- (ISH) and ICC-positive cells increased until after birth. During postnatal development, coinciding with innervation of the IL, the POMC mRNA level in the lobe, measured by quantitative ISH, increased about 4-fold to reach the adult value at weaning. The effects of acute or chronic postnatal treatment with a dopamine antagonist (haloperidol) or a dopamine agonist (bromocriptine) show that the physiological dopaminergic inhibitory control of POMC gene expression operates as early as postnatal day 5. The subsequent increase in mRNA levels despite the inhibitory innervation raises the question of the existence of some unknown positive regulation active during postnatal development.

Animals↗
PubMed1990

Case report 623. Osteitis condensans of the left clavicle (OCC).

A case of OCC in a 35-year-old woman is presented. Proof was obtained by open biopsy. This rare entity is benign and its etiology is still obscure. No definite association with osteitis pubis or osteitis condensans ilii has been reported. The involvement of the clavicle is invariably unilateral. The clinical and radiographic characteristics of this benign condition have been discussed and the differential diagnosis has been considered. Consideration should be given to the concept that if the imaging features are characteristic, as in this case, biopsy may not be necessary.

Adult↗
PubMed1990

Case report 588: Intracortical chondroma of the left femur.

A case of intracortical chondroma in the left femur in a 22-year-old man is presented. Proof was obtained by open biopsy. The issue of periosteal vs intracortical chondroma was discussed in depth, with emphasis on the radiographic appearances. The differential diagnosis of this benign intracortical lesion was also included. The histopathologic characteristics of this intracortical chondroma were described and a possible explanation for the unusual location of the cartilage lesion within the cortex was considered.

Adult↗
PubMed1990

Observations of the microwave emission of Venus from 1.3 to 3.6 cm.

Laboratory measurements of Steffes (1986) have suggested that the intensity and shape of the microwave spectrum of Venus might be especially sensitive to the subcloud abundance of constituents such as SO2 and gaseous H2SO4. It was likewise suggested that some variations of the shape of the emission spectrum might occur between 1.5 and 3 cm (10 to 20 GHz), a wavelength range which had previously only been sparsely observed. As a result, coordinated observations of Venus emission were conducted at four wavelengths between 1.35 cm (22.2 GHz) and 3.6 cm (8.42 GHz) using the 43-m NRAO antenna at Green Bank, West Virginia, and the 64-m antenna at NASA's Deep Space Communication Complex, Goldstone, California. In this paper, we report the methodology and results of these observations, and compare the results with other observations and with calculated emission spectra. We conclude that the observed emission spectrum is consistent with an average subcloud abundance of gaseous H2SO4 in equatorial and midlatitude regions which is approximately 5 ppm. It is suggested that additional measurements of atmospheric microwave opacity be made with the Pioneer-Venus Orbiter Radio Occultation experiment to search for temporal and spatial variations in gaseous H2SO4 abundance in the Venus atmosphere. An upper limit for the subcloud abundance of SO2 is also determined.

Astronomy↗
PubMed1990

Luteoma of pregnancy.

We have presented a case of luteoma of pregnancy, an uncommon ovarian lesion that is usually detected incidentally during cesarean section or postpartum tubal ligation. It is felt to be nonneoplastic, is hormonally stimulated, and regresses after childbirth. It is important to distinguish it from neoplastic lesions of the ovary that can occur in the same population, particularly steroid cell tumors, although this can be a difficult differential diagnosis.

Diagnosis, Differential↗
PubMed1990

Chondromyxoid fibroma: report of six cases with immunohistochemical studies.

Chondromyxoid fibroma is a rare benign bone tumor of uncertain histogenesis that typically presents as an eccentric lesion in the metaphysis of a long bone of a young adult. We report S-100 positivity in six cases of myxochondroid fibroma, a finding consistent with the cartilaginous nature of the lesion and its possible relation to chondroblastoma.

Adolescent↗
PubMed1990

The home health nurse clinician's role in the prevention of nonorganic failure to thrive.

Home health nurse clinicians are invaluable in the detection of children at risk for nonorganic failure to thrive (NOFTT). The literature has emphasized the role of hospital-based health care personnel in evaluating NOFTT, a strategy that relies heavily on the parent for initiation of services. Since one of the most commonly agreed-on causes of NOFTT is a disturbance in the mother-child relationship, case-finding efforts need to be community-based and less reliant on parental recognition. Because the most effective interventions take place in the child's home setting, the home health nurse clinician is in a unique position to assess the home environment for dysfunctional family interactions and behaviors and then to use the ongoing relationship with the family to implement prevention strategies for NOFTT, including teaching, modeling, and coaching effective parenting. Home-based nursing also provides the means for necessary follow-up of these families to ensure the success of the strategies.

Child↗
PubMed1990

Atypical radiographic appearances of tuberculous granulomas of bone.

We present four adults with tuberculous granulomas of bone. In three patients the granuloma involved the end of a long bone. The vertebral body and the right pedicle of the 10th thoracic vertebra were involved in the fourth patient. In all four the adjacent joint or the disk space was spared; hence the lesions mimicked bone neoplasms. Sclerotic changes, periosteal reaction and sequestration were present in three patients. Three of the four patients were not white. Since histologic specimens may not reveal mycobacteria, radiologists should alert orthopedic surgeons to the need to obtain material for culture at the time of biopsy of lesions that might be unusual manifestations of skeletal tuberculosis.

Adult↗
PubMed1990

Case report 603. Giant cell reparative granuloma of the distal end of right femur.

A GCRG of the femur in a 57-year-old man was described. He had undergone local radiotherapy and systemic chemotherapy for T-cell lymphoma of the jaw and scalp diagnosed 4 weeks previously. Since radiologically the lesion suggested an aggressive process, malignant lymphoma was the most probable preoperative diagnosis. In the differential diagnosis giant cell tumor, brown tumor of hyperparathyroidism, benign fibrous histiocytoma, and malignant fibrous histiocytoma were discussed in further detail. This histologically documented case of GCRG of the femur without any underlying process appears to be the first case reported in a long bone. It is unclear if the reparative process was primary or represented a reaction of the host bone to lymphoma which had completely responded to chemotherapy.

Diagnosis, Differential↗
PubMed1989

Expression of the oxytocin and vasopressin genes in the rat hypothalamus during development: an in situ hybridization study.

Oxytocin (OT)- and vasopressin (VP)-mRNAs were detected in the hypothalamus, during development, by in situ hybridization with synthetic oligonucleotide probes. The presence of VP- and OT-mRNAs was first detected in the supraoptic nucleus at E16 and E17 respectively, and simultaneously at E18 in the paraventricular nucleus. VP- (but not OT-) mRNA then appeared in the suprachiasmatic nucleus at E21, and OT- (but not VP-) mRNA, in the anterior commissural nucleus at time of birth. In the different nuclei, the relative distribution of cells containing OT- or VP-mRNA was comparable, from the earliest stages on, with that observed in the adult. These data suggest that the later appearance of mature OT (E20), versus VP (E16), reported in immunocytochemical studies, may not be due to a delayed transcription. Moreover, since the presence of both OT- and VP-prohormones has been reported at E16, the results support the idea of a rapid translation of both OT- and VP-mRNAs. In no location could OT- and VP-mRNAs be detected before final cell settlement; the possible role of environmental factors in final non-proliferative differentiation is discussed.

Animals↗