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S Zachariah

Publications and source records attributed to S Zachariah.

18 recordsLinked to original sources
PubMed2002

Evaluation of ventilator-associated lower respiratory tract infection and tracheobronchial aspiration of gastrointestinal contents.

STUDY OBJECTIVE: Ventilator-associated lower respiratory tract infection (LRTI) in a set up of respiratory intensive care unit was evaluated. Also the incidence of tracheobronchial aspiration of gastrointestinal contents was explored among these patients. DESIGN: Twenty eight patients admitted in the respiratory intensive care unit of referral teaching hospital were studied. All patients were evaluated for tracheobronchial aspiration of gastrointestinal contents in the initial 48 hours of initiating mechanical ventilation using methylene blue as marker and glucostix reagent strip. Protected endotracheal aspirate was secured after 48 hours of beginning of mechanical ventilation and was submitted for microbiological assay. RESULTS: Of the 28 mechanically ventilated patients, 82% were found to have developed LRTI. Aerobic gram-negative bacilli accounted for 79% of the infections, Klesiella responsible for 39% while Pseudomonas and Escherichia accounted for 18% each. The remaining 4% were caused by Acinetobacter. Gram-positive cocci were responsible for 21% of infection with Staphylococcus and enterococci 14% and 7% respectively. Tracheobronchial aspiration of GI contents was found to be present in 72% of the patients which was significantly correlated with the incidence of LRTI (p=0.014). Significant association was also found between the incidence of LRTI and mortality (p=0.05). CONCLUSION: The incidence of gastrointestinal aspiration was found to be high and correlation with LRTI was significant. Both glucostix reagent strip and methylene blue were observed to have same positivity rate.

Adolescent↗
PubMed2001

Human preadipocytes seeded on freeze-dried collagen scaffolds investigated in vitro and in vivo.

Currently, there is no adequate implant material for the correction of soft tissue defects such as after extensive deep burns, after tumor resection and in hereditary and congenital defects (e.g. Romberg's disease, Poland syndrome). The autologous transplantation of mature adipose tissue has poor results. In this study human preadipocytes of young adults were isolated and cultured. 10(6) preadipocytes were seeded onto collagen sponges with uniform 40 microm pore size and regular lamellar structure and implanted into immunodeficient mice. Collagen sponges without preadipocytes were used in the controls. Macroscopical impression, weight, thickness, histology, immunohistochemistry (scaffold structure, cellularity, penetration depth of the seeded cells) and ultrastructure were assessed after 24 h in vitro and after explantation at 3 and 8 weeks. Preadipocytes penetrated the scaffolds 24 h after seeding at a depth of 299+/-55 microm before implantation. Macroscopically after 3 and 8 weeks in vivo layers of adipose tissue accompanied by new vessels were found on all preadipocyte/collagen grafts. The control grafts appeared unchanged without vessel ingrowth. There was a significant weight loss of all grafts between 24 h in vitro and 3 weeks in vivo (p < 0.05), whereas there was only a slight weight reduction from week 3 to 8. The thickness decreased in the first 3 weeks (p < 0.05) in all grafts. The preadipocyte/collagen grafts were thinner but had a higher weight than the controls at this point in time. The histology showed adipose tissue and a rich vascularisation adherent to the scaffolds under a capsule. The control sponges contained only few cells and a capsule but no adipose tissue. Human-vimentin positive cells were found in all preadipocyte/collagen grafts but not in the controls, penetrating 1188+/-498 microm (3 weeks) and 1433+/-685 microm (8 weeks). Ultrastructural analysis showed complete in vivo differentiation of viable adipocytes in the sponge seeded with preadipocytes. Formation of extracellular matrix was more pronounced in the preadipocyte/collagen grafts. The transplantation of isolated and cultured preadipocytes within a standardised collagen matrix resulted in well-vascularised adipose-like tissue. It is assumed that a pore size greater than 40 microm is required, as preadipocytes enlarge during differentiation due to incorporation of lipids.

Adipocytes↗
PubMed2001

Influence of different biodegradable carriers on the in vivo behavior of human adipose precursor cells.

The correction of soft-tissue defects presents a challenge in plastic and reconstructive surgery. The implantation of isolated and culture-expanded adipose precursor cells is a solution to this problem because these cells differentiate into adipocytes when implanted in vivo. Appropriate scaffolds are needed in soft-tissue engineering to allow the differentiation of precursor cells. The optimal carrier needs to be defined. In this study, human preadipocytes were isolated and cultured. Three different carrier materials were seeded with 106 preadipocytes each and implanted in 42 nude mice. Sponges and nonwoven carriers based on hyaluronic acid modified by esterification (HYAFF 11) were compared with collagen sponges. Scaffolds without cells served as negative controls in the same animal. After 3 and 8 weeks, the grafts were explanted. Macroscopic appearance, weight, thickness, microscopy, immunohistochemistry, and TEM (scaffold structure, cellularity, penetration depth of the seeded cells, vascularization) were assessed and evaluated for differences in scaffold-cell interactions.Preadipocytes differentiated earlier in vitro when attached to HYAFF 11 scaffolds than to other carrier materials. Macroscopically, all preadipocyte constructs were yellowish and well vascularized, and the controls were white and avascular. Vessel formation was more pronounced around mature adipocytes. Microscopically, HYAFF 11 constructs showed a higher cell density than collagen constructs. The pores of the sponges contained more differentiated adipocytes than the nonwoven carriers, whereas the undifferentiated preadipocytes were more numerous in the nonwoven material. Penetration of adipose precursor cells was deeper and more homogeneous in HYAFF 11 scaffolds. Electron microscopy demonstrated well-differentiated adipocytes and large amounts of extracellular matrix in HYAFF 11 sponges.HYAFF 11 sponges supported the expansion and differentiation of the adipose precursor cells. This carrier is superior to the nonwoven carrier with regard to adipocyte differentiation and superior to the collagen sponge with regard to cellularity. This is a promising method for the reconstruction of soft-tissue defects. Modifications of the scaffold (larger pore size and coating with adipogenic factors) will be examined in further experiments.

Adipocytes↗
PubMed1997

Characterization of the oriC region of Mycobacterium smegmatis.

A 3.5-kb DNA fragment containing the dnaA region of Mycobacterium smegmatis has been hypothesized to be the chromosomal origin of replication or oriC (M. Rajagopalan et al., J. Bacteriol. 177:6527-6535, 1995). This region included the rpmH gene, the dnaA gene, and a major portion of the dnaN gene as well as the rpmH-dnaA and dnaA-dnaN intergenic regions. Deletion analyses of this region revealed that a 531-bp DNA fragment from the dnaA-dnaN intergenic region was sufficient to exhibit oriC activity, while a 495-bp fragment from the same region failed to exhibit oriC activity. The oriC activities of plasmids containing the 531-bp sequence was less than the activities of those containing the entire dnaA region, suggesting that the regions flanking the 531-bp sequence stimulated oriC activity. The 531-bp region contained several putative nine-nucleotide DnaA-protein recognition sequences [TT(G/C)TCCACA] and a single 11-nucleotide AT-rich cluster. Replacement of adenine with guanine at position 9 in five of the putative DnaA boxes decreased oriC activity. Mutations at other positions in two of the DnaA boxes also decreased oriC activity. Deletion of the 11-nucleotide AT-rich cluster completely abolished oriC activity. These data indicate that the designated DnaA boxes and the AT-rich cluster of the M. smegmatis dnaA-dnaN intergenic region are essential for oriC activity. We suggest that M. smegmatis oriC replication could involve interactions of the DnaA protein with the putative DnaA boxes as well as with the AT-rich cluster.

Bacterial Proteins↗
PubMed1997

ASCUS on cervical cytologic smears. Clinical significance.

OBJECTIVE: To determine the significance of the category atypical squamous cells of undetermined significance (ASCUS) in predicting the presence of underlying squamous intraepithelial lesion (SIL) and to determine the best follow-up method. STUDY DESIGN: Follow-up studies of all cervical cytologic smears with a diagnosis of ASCUS within 14 months were reviewed. RESULTS: SIL was diagnosed in 66.67% of ASCUS patients upon follow-up with biopsies with and without smears. SIL was diagnosed in 17.39% of ASCUS patients upon follow-up with smears only. CONCLUSION: Based on this study, ASCUS on smears serves as a good marker of underlying SIL. Follow-up studies with biopsies with and without smears appear to be more effective in detecting underlying low grade SIL than repeat smears only.

Biopsy↗
PubMed1996

Magnetic resonance imaging of syrinx associated with intramedullary metastases and leptomeningeal disease.

Intramedullary spinal cord metastasis with an associated syrinx diagnosed by magnetic resonance imaging (MR) is described. The patient had documented simultaneous leptomeningeal spread of malignant cells and intramedullary spinal cord metastasis with hyalinized blood vessels, venous dilatation, and cavitation detected by autopsy. Metastasis to the spinal cord is unusual, but well described. Syrinx associated with intramedullary spinal cord metastasis has been detected rarely. MRI of syrinx and intramedullary spinal cord metastasis, and the possible pathogenesis of these lesions are discussed.

Adenocarcinoma↗
PubMed1990

The use of gastric salvage cytology in the diagnosis of malignancy: a review of 731 cases.

Over an 8-yr period at the Houston Veterans Hospital, 731 endoscopic gastric salvage cytologies were performed in 671 patients, with surgical biopsy also done in 660. Seventy-six patients subsequently had tissue biopsy-proven or resection-proven malignancies. Salvage cytology had a sensitivity of 91% and a specificity of 100% for the detection of primary adenocarcinoma. Biopsy alone had a sensitivity of 92%; endoscopic gastric salvage cytology and surgical biopsy combined had a sensitivity of 100% in both primary and metastatic neoplasms. This study shows that the combination of endoscopic biopsy and salvage cytology increases the diagnostic accuracy for gastric carcinoma. Gastric salvage cytology requires minimal disruption of the routine endoscopic procedure and is therefore an easier and more rapid cytologic technique than gastric brushing cytology.

Adenocarcinoma↗
PubMed1990

Diagnosis of metastatic lesions to the stomach by salvage cytology. A report of three cases.

Secondary neoplasms of the stomach are rare and are often clinical and diagnostic problems. Three patients with bleeding "volcano-like" ulcers were diagnosed by combined endoscopic "salvage" cytology and surgical biopsy as having metastatic submucosal lesions from hematologic spread. The combination of endoscopic appearance, clinical findings, and tissue and cytologic examination can lead to the correct diagnosis. The results from these cases support the utility of this cytologic technique in combination with biopsy in this clinical setting.

Aged↗
PubMed1989

Fine-needle aspiration cytology of metastatic neoplasms in the breast.

Twenty cases of metastatic neoplasms in the breast were identified in a series of 1,034 fine-needle aspirations (FNAs) of the breast, of which 389 were malignant. Patients with breast carcinomas in whom metastasis to the contralateral breast developed were excluded from this study. This series consisted of 17 women and 3 men, ranging in age from 28 to 63 years (mean, 49 years). The tumors included oat cell carcinoma (three), melanoma (three), ovarian serous carcinoma (one), bronchogenic adenocarcinoma and squamous carcinoma (four and two, respectively), lymphoma (two), carcinoid (two), transitional cell carcinoma (one), plasma cell myeloma (one), and rhabdomyosarcoma (one). In two patients, the breast mass was the first manifestation of an extramammary cancer (two adenocarcinoma of the lung). Eleven patients died of disseminated cancer shortly after the breast metastasis was diagnosed. In most cases, the aspirates displayed the cytologic features characteristic of the primary tumors, thereby establishing the metastatic nature of the neoplasm. In four cases (two carcinoids, one myeloma, and one rhabdomyosarcoma), the cytologic features were difficult to differentiate from a primary breast carcinoma; however, the final diagnosis was established by electron microscopic examination and immunocytochemical studies on the aspirates. One case (adenocarcinoma of the lung) was misdiagnosed as primary breast carcinoma on both FNA and mastectomy specimen. Because metastatic neoplasms in the breast may mimic primary breast tumors, the authors recommend the following: (1) Evaluation of FNA of breast should be done with complete knowledge of the patient's clinical history. (2) The possibility of metastasis should be suspected in lesions with unusual cytologic patterns. (3) Ancillary studies on FNA can be helpful in interpreting selected cases.

Adult↗
PubMed1984

Effective penetration of doxycycline into the serum and aqueous humor.

Twenty-five human subjects of both sexes undergoing operations for senile cataract were selected for the present study. Doxycycline was administered orally and at various intervals its penetration into the serum and aqueous humor were determined. It was concluded that for achieving therapeutic concentrations in the serum, doxycycline can be given in the dosage of 200 mg on the first day followed by 100 mg every 24 hours. However, in order to achieve therapeutic concentrations in the aqueous humor, doxycycline should be administered in the dosage of 200 mg on the first day followed by 100 mg every 12 hours.

Administration, Oral↗
PubMed1975

[99mTc-sulfur-rhenium colloid and 111In-indium citrate in bone-marrow scintigraphy].

Bone marrow scinitigraphy using 111In-Indium-citrate and 99mTc-sulfur rhenium colloid was compared with each other in 6 male and 3 female patients. Our results in all patients were in favour of 111In-citrate which caused a better delineation of morphological details than 99mTc-sulfur rhenium colloid did. In the first days after intravenous administration of 111In-citrate, radioindium accumulated markedly in the pudendal region, this finding being more distinct in male patients than in female ones. On account of these results a considerable radiation dose has to be assumed in bone marrow scinitigraphy using 111In-citrate as long as the absorbed dose from 111In has not been estimated under consideration of the radioindium accumulation in the pudendal region. 111In-citrate should be applied in bone marrow scanning only exceptionally and 99mTc-sulfur rhenium colloid be preferred in the routine diagnostics of bone marrow.

Adult↗
PubMedDate not supplied

Ploidy studies by image analysis on fine needle aspirates of the breast.

Quantitative DNA analysis was performed on preoperative fine needle aspirates of 12 breast cancers and 1 benign lesion using the Cell Analysis Systems (CAS) Model 200 image analysis system. The smears were prepared on CAS slides, routinely processed for Papanicolaou staining, and then destained and restained with Feulgen stain after cytologic evaluation. Four cases were DNA diploid, 3 were tetraploid, 1 was diploid/tetraploid, and 5 were aneuploid. When compared to analysis of samples from the resected tumor, both DNA index and S-phase fraction were constant.

Biopsy, Needle↗